Improvement in joiners  clamps



PATENT (Darren.

GUSTAV A. ,NAUMANN, 0F sr. LOUIS, MISSOURI.

IMPROVEMENT IN JOINERS CLAMPS.

Specification forming part of Letters Patent N 0. 178,022, dated May 30,1876; application filed April 11, 1876.

To all whom it may concern:

Be it known that I, GUSTAV A. NAUMANN, of St. Louis, Missouri, haveinvented an Improvement in Joiners Clamps, of which the following is aspecification:

This invention is an improvement on patents issued to me dated andnumbered, re-

spectively, October 19, 1875, N 0. 169,027, and

March 14, 1876, No. 174,838.

Of the drawing, Figure 1 is a sectional elevation, showing the partslocked. Fig. 2 is a bottom plan of top plate with its operating parts inopen or unlocked condition. Fig. 3 is a detail view of manner offastening the front screw, Fig. 4 being a side elevation of the key usedto operate the slides.

A and B are the fixed and movable jaws, respectively. 0 and O are thefront and rear hand -screws, respectively. D and D are front and rearslides, which are to clamp the hand-screws. These slides are similar inconstruction, each having a nut-shaped portion with screw threadscorresponding to the threads of the handscrews, and as shown in Fig. 1.The action and movement of the slides D D is similar as in my lastpatent referred to; but the parts that operate said slides constitutingmy present improvement are as follows: Besides the threaded portion ofthe slides D D, I construct the remaining part thereof to each presentthe hook shaped shanks cl and d (SeeFig. 2.) The space hetween the hookends d and d is adapted to admitof a turn-key, d cross-shaped ordoublearmed in construction, and as shown in Figs. 1, 2, and 4. d d (seeFig. 4.) are the arms of the-key, acting or turning in the space leftbetween the two hooks of the slides, and consequently forcing saidslides apart in opposite directions. E is a spring, (see Figs. 1 and 2,)which serves to return the slides to original position.

To retain my operating parts a cover-plate, F, is screwed down upon thetop of the jaw and over the operating parts, said cover having properopening for the hand-screws, and

the screws as firmly as possible, and at same time not weakenunnecessarily the jaw: The front screw, when any article is clamped,tends to draw outor unloosen its hold in the lower jaw, while the strainof the other handscrew is downward. In my present joint I pass theforward screw, say, about two-thirds into the jaw, and hold it inposition by a staple, f which engages around the neck of the screw end,said staple having a broad bearing-surface, to act against the solidmaterial above. (See Fig. 3.) The rear screw need only then to haveajoint with the lower jaw sufficient to prevent said screw disengagingor slipping out of its place, and giving it as much solid bearing belowas possible. For this purpose I merely pass a pin, f through the jaw, toengage the neck end of the screw. (See Fig. 1.)

Thus constructed and arranged, the operation of the parts is as follows:The parts being iii locked position, (see Fig. 1,) the key (1 is on across-line with relation to the position of the book ends orslidesproper. To disengage the movable jaw from adjustment, the key istherefore turned, say, a quarter-turn, to the right; its arms d dengaging the hook end of the slides, force saine in opposite directionsaway from the hand-screws, and assume the unlocked position shown inFig. 2. In this position the key has its arms parallel with the slides,and is at a dead-point; and having compressedthe spring E, the movablejaw is sufficiently loosened to be adjusted to required positions alongthe hand-screws. To secure the movable jaw in adjusted position, the keyis turned so as to come to the position shown in Fig. 1, which enablesthe compressed spring to relock the slides in engagement with thehand-screws, and as indicated in Fig. 1.

Theadvantages achieved by this construction and operation of the parts(over my former patents) are, that the operation is more reliable, theclamp decisively and solidly holdin g the article. The adjustment of themovable jaw is greatly facilitated, and is positive by its slides indisengaging and engaging the threads; besides, the construction hereshown and described is far more simple, easier made, and cheaper. Inuse, the clamp-screw is much more durable, stronger, and effective inits parts, for it will be noted that the greater solid 0, and stationaryjaw A, arranged to operate portion of the jaw is retained-an advantagein the manner and for the purpose set forth.

of great importance in machines of this nature. In testimony of saidinvention I have here-- What I claim isunto set my hand. The turn-keydhaving arms d d, the slides GUSTAV A. NAUMANN.

D D, having hook-shanks 01 d the spring E, Witnesses:

plateor cover F, having slot f, in combination WILLIAM W. HERTHEL,

with movable jaw B, right-and-lcft screws 0 OHAs. F. MEISNER.

